Keyhole-guard



(No Model.) v

O. L. GOODRIDGE.

KBYHOLE GUARD.

No. 474,906. Patented May 17,1892.

Invert/1307:

Witnesses UNTTED STATES FATENT @rrrcn.

CHARLES L. GOODRIDGE, OF PORTLAND, MAINE.

KEYHOLE-GUARD.

SPECIFICATION forming part of Letters Patent No. 474,906, dated May 17,1892.

Application filed October 5, 1891. Serial No. 407,761. (No model.)

To all whom it may concern:

Be it known that I, CHARLES L. GOODRIDGE, a citizen of the UnitedStates, residing at- Portland, in the county of Cumberland and State ofMaine, haveinvented certain new and useful Improvements in Devices forClosing or Locking Keyholes; and I do hereby declare the following to bea full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

My invention relates to that class of keyhole-guards wherein a slidingplate is used to cover the keyhole, said plate being operated by the keywhen inserted from the side of the lock opposite to that where thesliding plate is mounted. In these keyhole-guards it is desirable toprovide a support for the inner end of the key and to prevent the wardof the key from interfering with the operation of the plate. In mydevice I mount the sliding plate on the inner surface of the lock, andaround the inside of the keyhole I place a boss, which forms a guide forthe sliding plate and which also forms a bearing for the spindle of thekey and offsets the ward of the key in such a way that it cannotinterfere with the slide.

In the accompanying drawings I have illustrated a lock to which myinvention has been applied.

In the drawings, Figure 1 represents myattachment in elevation on theinside of a plate of the lock, one side of thelock being removed. Fig. 2is a transverse section on line y y of Fig. i. Fig. 3 isa transversesection, the same as Fig. 2, showing my attachment on both sides of alock; and Fig. 4 is a view of the end of the key.

A represents the casin g of a tumbler-lock of any ordinary construction.The two sides of the look I shall hereinafterterm the plates of thelock.

B represents the main bolt of the lock,and C is the key. The key 0 has award which contains on the edge next the end of the key a projection 0,extending out from the end of the ward. The opposite edge 0', I preferto make plain, for the'reasons hereinafter shown. A sliding plate D isarranged to slide longitudinally, so that it may cover the keyhole a. Ihere show the plate D as held in guides against the inside of the plateof the lock andarranged so that it may slide to bring its inner endacross the keyhole. The lower edge of the plate D is held -by a flange dand the upper edge by a boss E, which is secured on the inner surface ofthe plate of the lock and surrounds the keyhole. The lower portion ofthe boss is offset, leaving a space in which the end of the plate Dslides. The particular-use of this boss will appear later on in thedescription.

Directly above the boss E is a sliding bolt F and tumbler G, similar inconstruction, as here shown, to the locking bolt and tumbler of anordinary tumbler-lock. The tumbler is operated by a spring II in theusual way.

I make no claim on the particular form of bolt and tumbler here shown,nor do I wish to limit myself thereto. The bolt F and tumbler G' areconstructed so that they will extend out from the plate of the lookaless dis tance than the surface of vthe boss. This is done in orderthat the inner ward of the key will clear them when the key is turned.If the inner edge of the ward is not straight, they must set insufliciently so that the ward will clear them. The bolt F is pushed backand forth by the projection c on the end of the ward, which followsaround the edge of the boss E, as shown in Fig. 2. The plate D isattached to the bolt F and moves back and forth with it.

It will now be clear how my device operates. Assuming that the key isinserted from the inside of the door in Fig. 2, the keyhole-lockingdevice will be outside. The projection c on the key extends down by theedge of the boss, but not sufficiently far to touch the plate D. As thekey turns to throw the main bolt forward the projection c on the wardalso throws the bolt F forward and slides the plate D over the'keyhole,looking it in place there as the bolt F is locked by the tumbler. Thekey may now be withdrawn and the outer keyhole will be closed and lockeduntil the door is unlocked from the opposite side, when the plate D willbe pushed back in the same manner that it was pushed forward.

In Fig. 3-1 show how my device may be applied to both keyholes of alook. It is necessary to have the inside edge of the ward straight, orso formed that it will swing free from the bolt and tumbler next to thekeyhole in which the key is inserted, as is seen in dotted lines in Fig.3. It will be seen that the boss E has two functionsname1y, on oneattached to said bolt for closing the keyhole, and a boss around theinside of said keyhole for offsetting the ward of the key, combined withthe key having a projection on its ward for throwing the bolt andlifting the tumbler, substantially as described.

In testimony whereof I affix my signature in 20 presence of twowitnesses.

CHARLES L. GOODRIDGE. Witnesses:

S. V. BATEs, B. S. HAYWARD.

